Workpiece treating apparatus

ABSTRACT

A workpiece treating arrangement includes a slatless rotatable drum which has centrifugal throwing wheels disposed therein for treating workpieces during rotation of the drum.

United States Patent 1 3, 93,296

Carpenter, Jr. 1 Sept. 26, 1972 1 WORKPIECE TREATING APPARATUS 1,343,3506/ 1920 Coburn ..51/ 13 [72] Inventor: James R Carpenter, Jr. 1,615,6221/1927 Greene ..51/164 Hagerstown Md 2,263,321 11/1941 Unger ..51/93,321,016 6/1943 DeBack ..51/164 X [73] Assignee: The CarborundumCompany, 2,441,578 /1948 Keefer ..51/13 Niagara Falls, N.Y. 2,449,7459/1948 Jewell ..51/13 3,007,285 11/1961 Bigelow ..51/13 [22] July17'1970 3,521,406 7/1970 Carpenter ..51 13 [21] Appl. N0.: 55,6993,585,758 6/1971 Harper ..51/13 Related Application Data PrimaryExaminer-James L. Jones, Jr. [63] Continuatiomimpart of 687,701 DecAttorney-David E. Dougherty and Robert E. Walter 4, 1967, Pat. No.3,521,406. ABSTRACT [52] US. CL, ..51/13, 51/9 A workpiece treatingarrangement includes aslatless [51] Int. Cl ..B24c 3/00 rotatable drumwhich has centrifugal throwing wheels [58] Field of Search ..51/9, 13,164 disposed therein for treating workpieces during rotation of thedrum.

[56] References Cited I UNITED STATES PATENTS 21 Claims, 4 DrawingFigures 1,297,400 3/1919 Ransohoff ..51/164 \L II"' I"''" 1'" u J 31*-05 46% f fiTWfififififiki-l i I 'e- "FHA "1 h 1 4 4 1:. ,tmii iill w1111 W3 1 50 i I m 1 I I l, k K, v ,24

PATENTEDsarzs I972 SHEET 2 (IF 2 WORKPIECE TREATING APPARATUSCROSS-REFERENCE TO RELATED APPLICATION BACKGROUND OF INVENTIONConventional universal type blast cleaning machines are suitable forhigh volume cleaning of small to medium size castings wherein themachines are of the continuous flow barrel type. These machines canhandle large tonnages of the same parts or miscellaneous parts andhandle them automatically. A particularly effective machine is disclosedin copending application Ser. No. now U.S. Pat. No. 3,585,758 dated June22, 1971, which includes a spiral infeed tube and a spiral exit tubewith the intermediate blast section being of the conventional slatconveyor construction. The machine disclosed in this applicationincludes such refinements and improvements that it is capable ofhandling a large variety of castings. More particularly this machine hassolved the problem of breakage and thrust inherent in previous designs.Despite the effectiveness of the machine a serious problem still exists.In this respect the slat conveyor, while working satisfactorily, is aconstant maintenance problem. Also, the design is a complex system ofindividual slats, chains, sprockets, bearings, etc., all requiringextensive engineering and creating manufacturing and maintenanceproblems. In addition, another problem of increasing importance is noiselevel. The present noise level being approximately 100 decibel on' the Cscale. Federal legislation is presently being considered which willrequire industrial noise levels to be 90 decibel on the A scale. Noisepollutes the air the same as particulate matter and legislation willpresently require lower noise levels.

' SUMMARY OF INVENTION Anobject of this invention is to provide aworkpiece treating arrangement which is particularly designed toovercome the above problems.

In accordance with this invention in place of the conventional slatconstruction the blasting section is a slatless drum and centrifugalthrowing wheels of the type disclosed in U.S. Pat. No. 3,521,406 aredisposed within the drum for treating workpieces therein during rotationof the drum.

The centrifugal throwing wheels may be mounted on a cantilevered tubewhich includes an elongated screw for distributing abrasive particlesfed into the tube to the individual throwing wheels. The tube and itsthrowing wheels may bemounted for oscillatory movement and may beconnected to a structural member which is suspended from an overheadmonorail to facilitate the insertion of the tube into the drum and itsremoval therefrom for maintenance purposes.

The drum may advantageously include an infeed tube at its entrance endof the type disclosed in U.S. Pat. No. 3,585,758 which includes a centerfeed tube. The infeed tube and slatless drum may advantageously be ofone-piece construction with each section including a spiral conveyoralthough the spiral conveyor in the work treating section would be ofgreater internal diameter than the spiral conveyor in the infeed tube.Drain holes may be provided to permit abrasive particles or othertreating media to drain into an oscillator conveyor which in turn mayhave a screen deck at the exit end of the drum to receive the treatedparts.

THE DRAWINGS FIG. 1 is a side elevation view of a workpiece treatingarrangement in accordance with this invention;

FIG. 2 is an end elevation view of the apparatus shown in FIG. 1; and

FIGS. 3-4 are cross-sectional views taken through FIG. 1 along the lines33 and 4-4, respectively.

DETAILED DESCRIPTION No. 3,585,758 this infeed tube arrangement includesthe bridging element or center feed tube 14 connected to the firstflight of spiral conveyor 16 so that the parts or workpieces that arefed therein will not be struck by the first flight of the spiralconveyor, thereby minimizing the possibility of breakage.

From the infeed tube 12 the parts are conveyed to the treating drum 18.Drum 18 and infeed tube 12 are of one-piece construction and differ fromeach other in that drum 18 includes a spiral conveyor 20 which is merelyof sufficient width or projects into the drum only an amount sufficientto convey the workpieces therethrough whereas spiral conveyor 16 in theinfeed tube 12 projects a substantial amount into the infeed tube asdescribed in U.S. Pat. No. 3,585,758. A plurality of openings 22 areprovided about the periphery of drum 18 to permit drainage of theabrasive particles and sand. Conversely, if the drum is of solidconstruction the flight of spiral conveyor 20 would function to move theabrasive particles and sand to the exit end of drum 18.

In addition to the many advantages obtained by utilizing the slatlessdrum 18 in place of the conventional slat conveyor or trough of priorart devices is the avoidance of the problem frequently attendant withprior art devices wherein with a slat conveyor some parts do not moveacross the conveyor to the exit end at a uniform speed and, at times,some parts even stay in the slat conveyor for hours. This problem isovercome with slatless drum 18 since, because of its cylindrical shape,the drum can include spiral conveyor 20 to insure a uniform "andcontinuous movement of the parts through the drum.

A further advantage with the inventive arrangement is that with priorarrangements the infeed spiral must push the parts or workpieces ontoand across the slat conveyor. This creates additional thrust loads onthe infeed tube section. With the inventive arrangement, however, thespiral 20 in the slatless drum, as noted above, uniformly moves allparts to the exit end of the machine. Since the infeed tube 12 and theblast drum 18 are of one-piece construction no high thrust loads arepresent other than the normal thrust required to screw the parts to theexit end of the drum.

At the exit end of the blast drum 18 the parts are dumped onto thescreen deck 24 of suitable oscillating conveyor 26. The abrasiveparticles fall through screen deck 24 and are recirculated in aconventional manner by elevator 28 through separating system 30 intofeed hopper 32. A plurality of rubber curtains 34 act to prevent theabrasive particles from being deflected out of drum 18. The cleanedparts are carried by the oscillating conveyor 26 by any suitable meanssuch as a further conveyor disposed at the discharge end of conveyor 26.

A feature which enables apparatus to function so effectively is therecent development of the type of centrifugal throwing wheels describedin U.S. Pat. No. 3,521,406, the details of which are incorporated hereinby reference thereto. In this respect slat conveyors had been necessarybecause the trough-like arrangement created an opening through which theblast wheels could project the abrasive particles. With a solid drumsuch as drum '18 no such openings are present. The development of thethrowing wheels described in U.S. Pat. No. 3,521,406 wherein each wheelis mounted directly on its motor shaft, however, permitted the wheels tobe inserted into the drum from either the open exit end or from theentrance end if desired.

As shown in FIG. 3 each throwing wheel 36 includes a motor 38 with arunnerhead 40 mounted directly on the motor shaft 42 and a plurality ofthrowing vanes 44 radially mounted on runnerhead 40. Abrasive particlesare supplied through spout 46 from support tube 48. The throwing wheel36 is mounted for universal movement about a plurality of axes asdescribed in U.S. Pat. No. 3,521,406.

As shown in FIG. 1 the individual throwing wheels 36 are mounted on acantilevered tube 48 which in turn is secured to a structural member 50.Structural member 50 is suspended from a monorail system 52 whichincludes horizontal track 54, wheels 56 and vertical mounting member 58.In this manner the entire unit comprising tube 48 and wheels 36 may beeasily moved into blast drum 18 during operation and out of the drum formaintenance or other purposes. Structural member 50 is so designed inshape as to conform to the size and shape of an opening at the exit endof the cabinet 60 so that when the tube 48 is inserted inside drum 18the opening in cabinet 60 is closed by structural member 50 to preventabrasive particles from ricocheting out of the blast drum. During usestructural member 50 is rigidly secured to the cabinet by bolts or othersuitable fastening means.

As shown in FIG. 3 mounted within hollow tube 48 is an elongated screwconveyor 62 or any other suitable conveying means to convey the abrasiveparticles fed into the tube to the spouts 46 of the individual throwingwheels 36. The space between the screw conveyor 62 and the inner surfaceof tube 48 is advantageously utilized to house electrical cables 64 tothe motors 38 and also to carry hoses 66 for feeding cooling air tomotors 38. Additionally, drive means 68 (FIG. 2) are provided tooscillate the entire unit of tube 48 and wheels 36 to give better blastcoverage. This oscillation means may take any suitable form and as shownin FIG. 4 may include a bearing surface 70 to which tube 48 is mounted,with arcuate slots 72 being in the bearing surface to control the amountof oscillation of tube 48.

' As shown in FIGS. 1-3 infeed tube 12 and drum section 18 may berotated by any suitable means such as -by gear drive 74 to tumble theworkpieces 11 being fed therethrough. During this rotation abrasiveparticles are supplied to the hollow interior of tube 48 from feedhopper 32 through an opening in cabinet 60 and through any suitablevalve such as gate valve 76 into elongated feed spout 78. Because of thewidened feed spout 78 the falling abrasive particles drop into the spouteven during oscillating of tube 48.

The workpiece treating arrangement 10 in accordance with this inventionhas a number of distinct advantages over the conventional prior art slatconveyor arrangements. For example the inventive arrangement eliminatesthe slat conveyor with its complex system of chains, sprockets, drives,rollers, slats and costly maintenance problems. Additionally, with theinventive arrangement there is continuous and positive movement of allwork through the barrel. Moreover, a much lower noise level is obtainedby mounting the blast wheels inside the blast drum 18 which in turn iswithin housing 60. Additionally, better and more uniform cleaning may beobtained by oscillating the throwing wheels. Further a complete unit isless expensive than an equivalent slat type continuous barrel.

What is claimed is:

l. A workpiece treating arrangement comprising a drum having an innersurface, means for rotating said drum, a centrifugal throwing wheel fortreating workpieces within said drum, a cantilevered tube for supportingsaid centrifugal throwing wheel, a spiral conveyor connected to theinner surface of said drum and extends over substantially the length ofsaid drum, an infeed tube connected to the entrance end of said drum, asecond spiral conveyor being connected to the inner surface of saidinfeed tube.

2. An arrangement as set forth in claim 1 wherein said second spiralconveyor projecting into said infeed tube a greater distance than thefirst spiral conveyor projects into said drum.

3. An arrangement as set forth in claim 2 wherein said drum and saidinfeed tube are of one piece construction.

4. An arrangement as set forth in claim 3 wherein a center feed tube isconnected to said second spiral conveyor coaxial with said infeed tube.

5. An arrangement as set forth in claim 3 wherein a plurality of drainholes are provided in said drum.

6. An arrangement as set forth in claim 3 wherein an oscillatingconveyor is disposed at the exit end of said drum, a screen deck beingon said oscillating conveyor, and rubber abrasive retaining curtainsbeing above said oscillating conveyor.

7. A workpiece treating arrangement comprising a drum, means forrotatingsaid drum, a plurality of throwing wheels for. treating workpieceswithin said drum, a cantilevered tube having a hollow interior, saidcantilevered tube supporting said centrifugal throwing wheels withinsaid drum, feed spouts for said throwing wheels communicating with theinterior of said cantilevered tube, means for distributing the treatingparticles through said cantilevered tube to said feed spouts.

8. An arrangement as set forth in claim 7 including traversing means formoving said cantilevered tube into and out of said drum.

9. An arrangement as set forth in claim 8 including feed means forfeeding treating particles into said cantilevered tube, and wherein saiddistributing means includes an elongated rotatable screw in saidcantilevered tube for distributing the treating particles therein tosaid feed spouts.

10. An arrangement as set forth in claim 9 including electrical cablesand hose means for said wheels disposed within the interior of saidcantilevered tube.

11. An arrangement as set forth in claim 9 including oscillating meansfor rotating said cantilevered tube and its throwing wheels.

12. An arrangement as set forth in claim 9 including a plurality ofmotors for driving said wheels, each motor having a drive shaft, each ofsaid wheels being mounted directly on the shaft of a respective motor.

13. An arrangement as set forth in claim 9 wherein said drum includes anexit end for the removal of workpieces and including a structural memberfor closing the exit end of said drum, and said cantilevered tube beingsecured to said structural member.

14. An arrangement as set forth in claim 13 wherein said structuralmember is suspended from a horizontal monorail for horizontal movementtoward and away from said drum.

15. A workpiece treating arrangement comprising a drum, means forrotating said drum, feed means for feeding work pieces into said drum,throwing wheel means disposed within said drum for treating theworkpieces during the rotation of said drum, said throwing wheel meansincludes a plurality of centrifugal throwing wheels each having arunnerhead, a plurality of throwing vanes radially mounted on eachrunnerhead, drive means for rotating said runnerheads and said vanes,particle feed means for supplying treating particles to said runnerheadsto be discharged from said vanes, and universal mounting means forpermitting each wheel to pivot about a plurality of axes.

16. A barrel for use in a workpiece treating arrangement comprising adrum having an inner face and having a plurality of drain holes, a firstspiral conveyor on the inner face of said drum along the length of saiddrum, an infeed tube at one end of said drum, said infeed tube having aninner face and an entrance end, said infeed tube and said drum being ofone piece construction, a second spiral conveyor on the inner face ofsaid infeed tube projecting into said infeed tube a greater distancethan said first spiral conveyor projects into said drum, a center feedtube connected to said conveyor, said center feed tube being coaxialwith said infeed tube, said second spiral conveyor comprising aplurality of flights, said flights including a first flight beingdisposed near the entrance end of said infeed tube and at least thefirst flight of said second spiral conveyor having an axial opening, anda bridging element disposed at the entrance of said infeed tube andextending to said axial opening of said first flight and connectedthereto.

17. An arrangement as set forth in claim 15 wherein said throwing wheelmeans is mounted on a cantilevered tube.

18. An arrangement as set forth in claim 17 including traversing meansfor moving said cantilevered tubeinto and out of said drum.

19. An arrangement as set forth in claim 17 wherein said cantileveredtube has a hollow interior and including a feed spout on each throwingwheel communicating with the interior of said cantilevered tube, andmeans for distributing the treating particles through said cantileveredtube to each feed spout.

20. An arrangement as set forth in claim 18 wherein said drum includesan inner surface and an entrance end and said arrangement includes aninfeed tube connected to the entrance end of said drum and a secondspiral conveyor being connected to the inner surface of said infeedtube.

21. An arrangement as set forth in claim 20 wherein a center feed tubeis connected to said second spiral conveyor coaxial with infeed tube.

1. A workpiece treating arrangement comprising a drum having an innersurface, means for rotating said drum, a centrifugal throwing wheel fortreating workpieces within said drum, a cantilevered tube for supportingsaid centrifugal throwing wheel, a spiral conveyor connected to theinner surface of said drum and extends over substantially the length ofsaid drum, an infeed tube connected to the entrance end of said drum, asecond spiral conveyor being connected to the inner surface of saidinfeed tube.
 2. An arrangement as set forth in claim 1 wherein saidsecond spiral conveyor projecting into said infeed tube a greaterdistance than the first spiral conveyor projects into said drum.
 3. Anarrangement as set forth in claim 2 wherein said drum and said infeedtube are of one piece construction.
 4. An arrangement as set forth inclaim 3 wherein a center feed tube is connected to said second spiralconveyor coaxial with said infeed tube.
 5. An arrangement as set forthin claim 3 wherein a plurality of drain holes are provided in said drum.6. An arrangement as set forth in claim 3 wherein an oscillatingconveyor is disposed at the exit end of said drum, a screen deck beingon said oscillating conveyor, and rubber abrasive retaining curtainsbeing above said oscillating conveyor.
 7. A workpiece treatingarrangement comprising a drum, means for rotating said drum, a pluralityof throwing wheels for treating workpieces within said drum, acantilevered tube having a hollow interior, said cantilevered tubesupporting said centrifugal throwing wheels within said drum, feedspouts for said throwing wheels communicating with the interior of saidcantilevered tube, means for distributing the treating particles throughsaid cantilevered tube to said feed spouts.
 8. An arrangement as setforth in claim 7 including traversing means for moving said cantileveredtube into and out of said drum.
 9. An arrangement as set forth in claim8 including feed means for feeding treating particles into saidcantilevered tube, and wherein said distributing means includes anelongated rotatable screw in said cantilevered tube for distributing thetreating particles therein to said feed spouts.
 10. An arrangement asset forth in claim 9 including electrical cables and hose means for saidwheels disposed within the interior of said cantilevered tube.
 11. Anarrangement as set forth in claim 9 including oscillating means forrotating said cantilevered tube and its throwing wheels.
 12. Anarrangement as set forth in claim 9 including a plurality of motors fordriving said wheels, each motor having a drive shaft, each of saidwheels being mounted directly on the shaft of a respective motor.
 13. Anarrangement as set forth in claim 9 wherein said drum includes an exitend for the removal of workpieces and including a structural member forclosing the exit end of said drum, and said cantilevered tube beingsecured to said structural member.
 14. An arrangement as set forth inclaim 13 wherein said structural member is suspended from a horizontalmonorail for horizontal movement toward and away from said drum.
 15. Aworkpiece treating arrangement comprising a drum, means for rotatingsaid drum, feed means for feeding work pieces into said drum, throwingwheel means disposed within said drum for treating the workpieces duringthe rotation of said drum, said throwing wheel means includes aplurality of centrifugal throwing wheels each having a runnerhead, aplurality of throwing vanes radially mounted on each runnerhead, drivemeans for rotating said runnerheads and said vanes, particle feed meansfor supplying treating particles to said runnerheads to be dischargedfrom Said vanes, and universal mounting means for permitting each wheelto pivot about a plurality of axes.
 16. A barrel for use in a workpiecetreating arrangement comprising a drum having an inner face and having aplurality of drain holes, a first spiral conveyor on the inner face ofsaid drum along the length of said drum, an infeed tube at one end ofsaid drum, said infeed tube having an inner face and an entrance end,said infeed tube and said drum being of one piece construction, a secondspiral conveyor on the inner face of said infeed tube projecting intosaid infeed tube a greater distance than said first spiral conveyorprojects into said drum, a center feed tube connected to said conveyor,said center feed tube being coaxial with said infeed tube, said secondspiral conveyor comprising a plurality of flights, said flightsincluding a first flight being disposed near the entrance end of saidinfeed tube and at least the first flight of said second spiral conveyorhaving an axial opening, and a bridging element disposed at the entranceof said infeed tube and extending to said axial opening of said firstflight and connected thereto.
 17. An arrangement as set forth in claim15 wherein said throwing wheel means is mounted on a cantilevered tube.18. An arrangement as set forth in claim 17 including traversing meansfor moving said cantilevered tube into and out of said drum.
 19. Anarrangement as set forth in claim 17 wherein said cantilevered tube hasa hollow interior and including a feed spout on each throwing wheelcommunicating with the interior of said cantilevered tube, and means fordistributing the treating particles through said cantilevered tube toeach feed spout.
 20. An arrangement as set forth in claim 18 whereinsaid drum includes an inner surface and an entrance end and saidarrangement includes an infeed tube connected to the entrance end ofsaid drum and a second spiral conveyor being connected to the innersurface of said infeed tube.
 21. An arrangement as set forth in claim 20wherein a center feed tube is connected to said second spiral conveyorcoaxial with infeed tube.